There are a lot of security issues in block cipher algorithm.Security analysis and enhanced design of a dynamic block cipher was proposed.Firstly,the safety of ciphertext was enhanced based on confusion substitution o...There are a lot of security issues in block cipher algorithm.Security analysis and enhanced design of a dynamic block cipher was proposed.Firstly,the safety of ciphertext was enhanced based on confusion substitution of S-box,thus disordering the internal structure of data blocks by four steps of matrix transformation.Then,the diffusivity of ciphertext was obtained by cyclic displacement of bytes using column ambiguity function.The dynamic key was finally generated by using LFSR,which improved the stochastic characters of secret key in each of round of iteration.The safety performance of proposed algorithm was analyzed by simulation test.The results showed the proposed algorithm has a little effect on the speed of encryption and decryption while enhancing the security.Meanwhile,the proposed algorithm has highly scalability,the dimension of S-box and the number of register can be dynamically extended according to the security requirement.展开更多
A fast authentication mode based on Multi-Block Chaining (MBC) is put forward; and its security is proved. The MBC mode is for new generation block cipher algorithms. Its speed is about 13% faster than that of the aut...A fast authentication mode based on Multi-Block Chaining (MBC) is put forward; and its security is proved. The MBC mode is for new generation block cipher algorithms. Its speed is about 13% faster than that of the authentication modes in common use (for example, cipher block chaining-message authentication code mode). The dependence test results meet the requirement. The MBC mode is complete; its degree of ava-lanche effect is about 0.9993; its degree of strict avalanche criterion is 0.992 or so. The frequency test results indicate that the output generated by the MBC mode has uniformity. The binary matrix rank test results imply that it is linear independent among disjoint sub-matrices of the output. Maurer’s universal statistical test results show that the output could be significantly compressed without loss of information. Run test, spectral test, non-overlapping template matching test, overlapping template matching test, Lempel-Ziv compression test, linear complexity test, serial test, approximate entropy test, cumulative sums test, random excursions test and random excursions variant test results fulfill the requirements of all. Therefore the MBC mode has good pseudo-randomness. Thus the security of MBC mode is verified by the way of statistical evaluation.展开更多
For the published block cipher algorithm, two kinds of round functions have been researched.Block ciphers in network environments are taking more risks than ever before because of their initialization key's distri...For the published block cipher algorithm, two kinds of round functions have been researched.Block ciphers in network environments are taking more risks than ever before because of their initialization key's distribution in the internet.The security of block cipher algorithm is affected by linear bias and nonlinear bias which are restricted by confusion layer and diffusion layer.This article takes an approach on how block cipher's two round structures are initially transformed when they fuse into LFSR.The SP structure can be considered two F functions in one Feistel round function which combines both right and left of origin data transformation.Furthermore, the round number linear function and nonlinear function of Feistel and SP structure are compared.The merit of SP structure is that it can fuse in LFSR as a nonlinear filter without memory.展开更多
基金supported in part by National Natural Science Fundation of China under Grant No.61202458,61403109
文摘There are a lot of security issues in block cipher algorithm.Security analysis and enhanced design of a dynamic block cipher was proposed.Firstly,the safety of ciphertext was enhanced based on confusion substitution of S-box,thus disordering the internal structure of data blocks by four steps of matrix transformation.Then,the diffusivity of ciphertext was obtained by cyclic displacement of bytes using column ambiguity function.The dynamic key was finally generated by using LFSR,which improved the stochastic characters of secret key in each of round of iteration.The safety performance of proposed algorithm was analyzed by simulation test.The results showed the proposed algorithm has a little effect on the speed of encryption and decryption while enhancing the security.Meanwhile,the proposed algorithm has highly scalability,the dimension of S-box and the number of register can be dynamically extended according to the security requirement.
基金Supported by the National Hi-Tech Research & Devel-opment Plan of China (863 Project) (No.2003AA143040) and Jiangsu Provincial Key Laboratory of Network & Information Security (No.BM2003201).
文摘A fast authentication mode based on Multi-Block Chaining (MBC) is put forward; and its security is proved. The MBC mode is for new generation block cipher algorithms. Its speed is about 13% faster than that of the authentication modes in common use (for example, cipher block chaining-message authentication code mode). The dependence test results meet the requirement. The MBC mode is complete; its degree of ava-lanche effect is about 0.9993; its degree of strict avalanche criterion is 0.992 or so. The frequency test results indicate that the output generated by the MBC mode has uniformity. The binary matrix rank test results imply that it is linear independent among disjoint sub-matrices of the output. Maurer’s universal statistical test results show that the output could be significantly compressed without loss of information. Run test, spectral test, non-overlapping template matching test, overlapping template matching test, Lempel-Ziv compression test, linear complexity test, serial test, approximate entropy test, cumulative sums test, random excursions test and random excursions variant test results fulfill the requirements of all. Therefore the MBC mode has good pseudo-randomness. Thus the security of MBC mode is verified by the way of statistical evaluation.
文摘For the published block cipher algorithm, two kinds of round functions have been researched.Block ciphers in network environments are taking more risks than ever before because of their initialization key's distribution in the internet.The security of block cipher algorithm is affected by linear bias and nonlinear bias which are restricted by confusion layer and diffusion layer.This article takes an approach on how block cipher's two round structures are initially transformed when they fuse into LFSR.The SP structure can be considered two F functions in one Feistel round function which combines both right and left of origin data transformation.Furthermore, the round number linear function and nonlinear function of Feistel and SP structure are compared.The merit of SP structure is that it can fuse in LFSR as a nonlinear filter without memory.
